Investigation of clinicopathological parameters alongside with p53 expression in primary and recurrent keratocysticodontogenic tumours.

BACKGROUND Keratocysticodontogenic tumor (KCOT) is one of the most common odontogenic cysts and has a high recurrence rate after various treatment methods. Some studies have been conducted to identify the predictive factors of recurrence. In this study, the clinicopathological and immunohistochemical features of primary and recurrent KCOTs are analyzed, including immunohistochemically expression of p53 protein in cyst-lining epithelial cells in order to find more markers to predict the specific behaviour and greater tendency for recurrence. METHODS In this descriptive analytic study, a total of 78 archived specimens of KCOTs, including 52 primary KCOT with no registered recurrences to date and 26 recurrent KCOT were selected. The clinical data and histopathological features of the epithelial lining and connective tissue wall were analyzed. Immuonohistochemical staining intensity distribution (SID) score for p53-positive cells were calculated for both groups. Results were analyzed by T-test, Chi-square, and Fisher's exact test. RESULTS There were no statistically significant differences between primary and recurrent cases in terms of age (P = 0.181), gender (P = 0.744), and anatomical location (P = 0.294). In the histopathological assessment, epithelial budding (P = 0.001), daughter cysts (P = 0.013), and odontogenic rests (P = 0.036) were significantly more common in recurrent KCOTs. Immunohistochemical staining for p53 show statistically significant difference between the two groups (P = 0.041). CONCLUSION In this study, some predictive factors of recurrence of KCOTs such as epithelial budding, daughter cyst and odontogenic rests were found. Furthermore, the evaluation of p53 expression in KCOT at the time of diagnosis was helpful for the prediction of recurrence.